One of the Hatton Garden raid ringleaders was obsessed with crime and would sleep in his mum's dressing gown and a fez hat, a court heard.
Daniel "Danny" Jones, 60, has admitted his role in the largest burglary in English history,which took place over the Easter weekend.
He was also obsessed with the army and keeping fit - often going to bed in a sleeping bag on his bedroom floor, his friend of 30 years, Carl Wood, 58, told London's Woolwich Crown Court.
Jones was "eccentric to extremes", and would speak to his white-haired terrier dog, Rocket, as if it were human, the court heard.
Wood, a married father of two, told jurors he first met Jones in a pub around 30 years ago, and the two became friends over their mutual interest in "keeping fit".
But soon after he was diagnosed with Crohn's disease, aged around 24, Wood had to reduce his physical activity and instead he and Jones would go for walks together, often to a nearby garden centre.
Bearded Wood, dressed in a beige V-neck sweater, white open collar shirt and dark trousers, told the court Jones is a very "caring" and "sensitive" guy.
Wood said: "Danny is a very sensitive guy, a very funny man. Eccentric to extremes, that everyone who knew Danny would say he was mad. He would go to bed in his mother's dressing gown with a fez on."
He continued: "He would read palms, tell people he could read their fortunes - bit of a Walter Mitty.
"Danny was studying crime all the time in his room, reading books about it, watch films and go on the internet."
The court heard the two men would often speak on the phone, but Wood explained this as "general chit chat", and as them arranging to go on a walk. The prosecution allege that the series of phonecalls involved plotting the Hatton Garden raid.
Referring to a call in early January, Nick Corsellis, defending, asked: "Were you discussing the planning of the largest burglary in English history?"
Wood replied: "No I was not. If I wasn't going on a walk, generally I was visiting my mum, with my wife or my children, or in the vicinity of my house. My life never changed other than that."
Wood, who was in debt and had financial issues at the beginning of the year, told the court he knew Jones was obsessed with crime, but that they never discussed this.
"He would tell me from time to time what he had been up to, but I never asked," said Wood.
Wood is accused of being one of the men who broke into Hatton Garden Safe Deposit on the night of April 2. He is alleged to have also returned on the night of April 4, but walked away from the job after finding the fire escape door closed.
The prosecution argue that a suspect identified as "Man F" in CCTV footage of the burglary is Wood.
Wood, of Elderbek Close, Cheshunt, Hertfordshire, is charged with conspiracy to commit burglary, and one count of conspiracy to convert, conceal or transfer criminal property.
Ringleaders Brian Reader, John "Kenny" Collins, 75, Jones and Terry Perkins, 67, have pleaded guilty to conspiracy to commit burglary at Hatton Garden Safe Deposit between 17 May 2014 and 7.30am on April 5 this year.
William Lincoln, 60, of Winkley Street, Bethnal Green, east London; and Jon Harbinson, 42, of Beresford Gardens, Benfleet, Essex, are on trial accused of the same offence. A fourth man, plumbing engineer Hugh Doyle, 48, of Riverside Gardens, Enfield, north London, is jointly charged with them on one count of conspiracy to conceal, convert or transfer criminal property between January 1 and May 19, this year.
He also faces an alternative charge of concealing, converting or transferring criminal property between April 1 and May 19, this year
One of the thieves, a red-haired man known only as Basil, has not yet been identified.
Collins of Bletsoe Walk, Islington; Jones of Park Avenue, Enfield; Perkins of Heene Road, Enfield and Reader of Dartford Road, Dartford, are due to be sentenced at a later date.
A Barclaycard statement for Wood showed that he was £8,890 in debt earlier this year.
He explained that he was receiving £320 per fortnight in disability pension on account of his suffering from Crohn's Disease and only being able to work "spasmodically".
Saying that he does not have a trade, Wood added: "I do a bit of painting and decorating - just a general dogsbody."
He described the disease as "very painful and debilitating", adding: "It feels like a mouthful of ulcers with a bottle of vinegar in your mouth."
The court heard that Wood has two grown up daughters, Sophia and Louise, and that his mother is in a care home in nearby Ware.
When asked to describe her condition, he starting crying saying: "My mother has got Alzheimer's. She is bedridden, has been for four years."
Referring to a series of phone calls exchanged between Wood and Jones, Mr Corsellis put it to his client: "Do we understand that any communication you had with Mr Jones was either about exercise, gossip, chatting about sport ... Nothing of relevance?"
"Nothing whatsoever," replied Wood.
He also put it to Wood: "(The prosecution case is) you are in the loop. You are being updated by Mr Jones about this conspiracy. Is there any truth to that suggestion?"
Wood responded: "None whatsoever."
When asked if he had any expertise in electronics, alarms, or engineering, Mr Wood said: "No."
Some of the calls that Wood received on his "cheap Tesco" mobile phone from Jones were made shortly after Jones had also called Perkins or Collins.
But Wood, who rides a black motorcycle, told jurors he did not know either man, and had never met them.
Although Wood told the jury the majority of calls between him and Jones were concerned with the arrangement of walks and general chit chat, he recalled the details of one on March 28.
He told the court that during this call he invited Jones to attend a barbecue at his house on Easter Saturday - two nights after the gang first gained entry to 88-90 Hatton Garden.
Wood told the court: "He said he was having murders at home - arguments. Val, his wife, was an agoraphobic who was on quite a lot of pills for nerves. She would phone him all the time.
"He said he was in the middle of doing something important that involved a lot of money. And 'she is keeping on at me. She is on at me all the time. I have had enough, I can't take any more'."
Wood explained that because he was not feeling too well, he cut the conversation short but invited Jones to attend the barbecue at his house because it sounded like he was going to leave.
Referring to CCTV footage of the raid, Mr Corsellis asked his client: "Are you Male F?"
"No," came the reply.
"Were you present as part of this burglary team on either the first night or the second night?" Mr Corsellis asked.
Wood replied: "(I) full stop wasn't there at all."
Mr Corsellis continued: "Your defence is 'It is not me, I wasn't there. I have an alibi - I was at home'."
"Yes," said Wood.
The trial continues tomorrow with Wood still giving evidence.